<?php
class Encrypt {

  function xcrypt($encrypt, $source) {
    // encrypt or decrypt a string $source
    // If $encrypt is 1, then we're encrypting; otherwise we're decrypting
    $universe = "tudLEBxcn1ehi2Ny8Q0sJKpHz7aAjvCfkb5P4I36oFG- 9qDgVwlmrT_RSMUO";
    $cryptkey = "23 21 04 07 49 22 48 30 60";
    
    // double universe length so that when encrypting from the left half or decrypting from the
	// right, we never have to wrap around
    $universe .= $universe;
    $result = "";
    $foundloc = 0;
    
    // encrypt goes to the right, decrypt goes to the left
    
    // encrypt
    if ($encrypt == 1) {
      for ($i = 0; $i < strlen($source); $i++) {
	$foundloc = strpos ( $universe, substr ( $source, $i , 1)) + intval(substr($cryptkey, ($i % 9) * 3, 2));
	if ($foundloc == FALSE) {
	  echo "Error: your user name or password contains characters other than letters, numbers, spaces, dashes, and underscores. Please use the Back button on your browser to back up and enter different values.";
	  return(FALSE);
	}
	$result .= substr($universe, $foundloc, 1) ;
      }
      // decrypt
    } else {
      for ($i = 0; $i < strlen($source); $i++) {
	$foundloc = strpos ( $universe, substr ( $source, $i , 1), 61) - intval(substr($cryptkey, ($i % 9) * 3, 2));
	if ($foundloc == FALSE) {
	  echo "Error: your user name or password contains characters other than letters, numbers, spaces, dashes, and underscores. Please use the Back button on your browser to back up and enter different values.";
	  return(FALSE);
	}
	$result .= substr($universe, $foundloc, 1);
      }
    }
    
    return ($result);
  }
}
?>